1. Field of the Invention
The present invention relates to commercial ovens, more specifically ovens which are used in commercial enterprises where rapid heating and browning are required.
2. Description of the Related Art
Traditional conveyor ovens, used to cook pizza and other similar product, rely on either high velocity hot air, high thermal mass heating elements (medium wave infrared) or thermal, natural convection technology, to process food. These ovens employ a conveyor that moves food through a heated cavity to facilitate continuous (assembly line type) cooking with minimum operator involvement. Most of the ovens also provide a door in the side of the cavity to load food for quick browning, thus, bypassing the conveyor.
While the referenced cooking technologies are effective at cooking a wide range of products they typically take between 6 and 12 minutes to cook a pizza, a food which represents the majority of the cooking applications. This time frame does not fit into a xe2x80x98made to orderxe2x80x99 environment and requires the operator to cook a large number of product (pizza) and hold them to satisfy demand during peak periods. Many operators that already serve xe2x80x9cfast foodxe2x80x9d, i.e., hamburgers, would like to offer pizza on the menu, but due to the relatively long cook times and the subsequent need to hold the product, which degrades quality, they do not. What is needed is a high speed conveyor oven that can cook product (pizza) in less than 3 minutes, produces results similar to more traditional cooking methods and provides key features of traditional conveyor ovens. This would allow many operators to offer high quality xe2x80x9cmade to orderxe2x80x9d pizza, expanding sales and profits.
There are high speed ovens using high power density, low mass heaters, including the Amana Wave(trademark) oven, that are capable of achieving pizza cook times of 3 minutes or less, however, they are either not conveyorized and/or require the application of a turntable within the cooking environment to achieve cooking uniformity. They also do not typically brown food, for example, the sides of a pizza crust being cooked in the oven because the direction of energy directed toward the pizza is perpendicular to the cooking surface. These constraints restrict their acceptance as a high speed alternative to traditional conveyor ovens.
There have been attempts to seek to augment traditional and well known conveyor ovens by increasing the operating temperature and/or velocity of the heated air to accelerate cooking. This has the effect of producing faster browning of the cheese but the central sections of the food remain under-cooked or under-heated.
Still other attempts involve combining microwave and hot air convection in a single non-conveyor cavity. While this accelerates cooking times it tends to have a negative effect on dough quality and still restricts the operator to xe2x80x98batchxe2x80x99 type, or xe2x80x9cone-at-a-timexe2x80x9d cooking.
The novel aspect of the present invention is the combined application of convection and radiant heating technology that has not been applied to conveyor ovens previously. Moreover, the use of a specifically configured arrangement of halogen lamps and formed reflectors, with the capability of illuminating the area described, is presently not available, with the exception to one described in U.S. Pat. No. 5,721,805.
The combination and unique design/application of these technologies provides an oven that can cook a high profit margin food product (pizza for example) in a time frame that provides operators a xe2x80x98make to orderxe2x80x99 product instead of cooking and holding. This benefit should provide increased market penetration and new avenues of profit for restaurant owners and operators.
The Combination High Speed Infrared and Convection Conveyor Oven of the present invention overcomes the problems of the prior art, and meets the above described needs. The invention described utilizes the combination of two types of heat transfer technology, convection and radiation, operating in unison within a single cavity and employing a conveyor to move food through a series of heat zones. Stage 1 heat zone is predominantly convection. Stage 2 heat zone is a combination of convection and short to mid wave infrared (IR). The shorter wavelength IR is emitted from a specifically configured arrangement of quartz halogen lamps and reflectors, referred to as the xe2x80x98Upper Radiant Heating Elementxe2x80x99.